Abstract: An NMR DNP-MAS probe head (10) has an MAS stator (2) for receiving an MAS rotor (3) having a sample substance in a sample volume (4), and a hollow microwave waveguide (5)? for feeding microwave radiation through an opening (5a) of the microwave waveguide into the sample volume, an axially expanded rod-shaped microwave coupler (6) located in the opening made of dielectric material, characterized in that the microwave waveguide has a conically tapered hollow transition piece for coupling in an HE 11 mode, into which the microwave coupler projects at an all-round radial distance to the opening of the microwave waveguide. It is thus possible, in a surprisingly simple manner and by means of readily available technical means, to irradiate a considerably higher microwave energy in the HE 11 mode into the NMR measuring sample than by means of the known arrangements.

Abstract: An NMR (nuclear magnetic resonance) probe head has a microwave resonator with at least two elements which are reflective in the microwave range, at least one of which is focusing. The reflective elements at least partly delimit a resonance volume of the microwave resonator. At least one of the reflective elements is a DBR (“Distributed Bragg Reflector”), and the NMR probe head has at least one NMR coil integrated into the DBR. The NMR detection coil can thereby be positioned particularly near to the sample and the distortions of the static field by resonator components are reduced, such that the detection sensitivity and the spectral resolution of the experiment are significantly improved.

Abstract: In a method for operating a heatable exhaust-gas sensor, which supplies at least one measuring signal and in which a sensor heater is operated using a pulse-width modulated operating voltage, the detection of the at least one measuring signal has priority over the supply of the pulse-width modulated operating voltage for sensor heater, and at least during a predefined time window in which the measuring signal is detected, the supply of the pulse-width modulated operating voltage for the sensor heater is suppressed using a blocking signal.

Abstract: An NMR DNP-MAS probe head (10) has an MAS stator (2) for receiving an MAS rotor (3) having a sample substance in a sample volume (4), and a hollow microwave waveguide (5)? for feeding microwave radiation through an opening (5a) of the microwave waveguide into the sample volume, an axially expanded rod-shaped microwave coupler (6) located in the opening made of dielectric material, characterized in that the microwave waveguide has a conically tapered hollow transition piece for coupling in an HE 11 mode, into which the microwave coupler projects at an all-round radial distance to the opening of the microwave waveguide. It is thus possible, in a surprisingly simple manner and by means of readily available technical means, to irradiate a considerably higher microwave energy in the HE 11 mode into the NMR measuring sample than by means of the known arrangements.

Abstract: An NMR (nuclear magnetic resonance) probe head has a microwave resonator with at least two elements which are reflective in the microwave range, at least one of which is focusing. The reflective elements at least partly delimit a resonance volume of the microwave resonator. At least one of the reflective elements is a DBR (“Distributed Bragg Reflector”), and the NMR probe head has at least one NMR coil integrated into the DBR. The NMR detection coil can thereby be positioned particularly near to the sample and the distortions of the static field by resonator components are reduced, such that the detection sensitivity and the spectral resolution of the experiment are significantly improved.

Abstract: A method for producing hyperpolarized sample material for use in magnetic resonance investigations involves preparing a target material containing high ? nuclei with a short T1, a polarizing agent with a broad EPR line, and low ? nuclei with a long T1. The polarizing agent in the target material is irradiated with microwave radiation, wherein the target material is at a cryogenic temperature and exposed to a static magnetic field B0?4.0 T, thus polarizing the high ? nuclei by DNP, and the polarization is transferred from the high ? nuclei to the low ? nuclei by Cross Polarization. A dissolved sample material is prepared containing the hyperpolarized low ? nuclei from the target material. Nuclei with a long longitudinal relaxation time T1 can thereby be quickly hyperpolarized to a high polarization level.

Abstract: In a method for operating a heatable exhaust-gas sensor, which supplies at least one measuring signal and in which a sensor heater is operated using a pulse-width modulated operating voltage, the detection of the at least one measuring signal has priority over the supply of the pulse-width modulated operating voltage for sensor heater, and at least during a predefined time window in which the measuring signal is detected, the supply of the pulse-width modulated operating voltage for the sensor heater is suppressed using a blocking signal.

Abstract: A method for producing hyperpolarized sample material for use in magnetic resonance investigations involves preparing a target material containing high ? nuclei with a short T1, a polarizing agent with a broad EPR line, and low ? nuclei with a long T1. The polarizing agent in the target material is irradiated with microwave radiation, wherein the target material is at a cryogenic temperature and exposed to a static magnetic field B0?4.0 T, thus polarizing the high ? nuclei by DNP, and the polarization is transferred from the high ? nuclei to the low ? nuclei by Cross Polarization. A dissolved sample material is prepared containing the hyperpolarized low ? nuclei from the target material. Nuclei with a long longitudinal relaxation time T1 can thereby be quickly hyperpolarized to a high polarization level.

Abstract: A resonator assembly for executing measurements on a sample within a constant magnetic field B0 by means of magnetic resonance is disclosed. It comprises a resonator portion defining a longitudinal axis and an axial direction. The resonator portion has, along the axial direction, a hollow cavity for exciting electron resonance within the sample. A coupling portion is provided adjacent the resonator portion and has, along the longitudinal axis, a stepped through being electrically conductive at its inner surface. A first, middle section of the stepped through configures the hollow cavity. A second and a third, lateral section adjacent axially opposed sides of the hollow cavity are each dimensioned such that a basic mode being resonant within the hollow cavity is unable to propagate within the second and the third section. A coil is wound around the resonator portion for additionally exciting a nuclear resonance within the sample.

Abstract: A resonator assembly for executing measurements on a sample within a constant magnetic field B0 by means of magnetic resonance is disclosed. It comprises a resonator portion defining a longitudinal axis and an axial direction. The resonator portion has, along the axial direction, a hollow cavity for exciting electron resonance within the sample. A coupling portion is provided adjacent the resonator portion and has, along the longitudinal axis, a stepped through being electrically conductive at its inner surface. A first, middle section of the stepped through configures the hollow cavity. A second and a third, lateral section adjacent axially opposed sides of the hollow cavity are each dimensioned such that a basic mode being resonant within the hollow cavity is unable to propagate within the second and the third section. A coil is wound around the resonator portion for additionally exciting a nuclear resonance within the sample.

Abstract: A probe head for nuclear magnetic resonance measurements comprises a sample holder having a stator and a rotor. The rotor is journalled for rotation about an axis of rotation within the stator. It is adapted for receiving a sample substance. The axis of rotation is inclined by an angle with respect to a longitudinal axis of the probe head. The stator is configured as a dielectric resonator.

Abstract: A probe head for nuclear magnetic resonance measurements comprises a sample holder having a stator and a rotor. The rotor is journalled for rotation about an axis of rotation within the stator. It is adapted for receiving a sample substance. The axis of rotation is inclined by an angle with respect to a longitudinal axis of the probe head. The stator is configured as a dielectric resonator.

Abstract: A probehead for nuclear magnetic resonance measurements has a network. The network comprises in series an NMR coil for receiving a sample, a line resonator as well as a probehead terminal. The line resonator is configured as a delay line.

Abstract: A probehead for nuclear magnetic resonance measurements has a network. The network comprises in series an NMR coil for receiving a sample, a line resonator as well as a probehead terminal. The line resonator is configured as a delay line.